The present invention relates to the control of calls to communication devices, and more particularly, to the control of calls over IP networks using the SIP protocol. Within a network architecture, a company may want to provide a network application to customers who have legacy systems that are incapable of providing the desired network application. In these cases the user would be required to install proprietary equipment and/or software enabling them to implement the desired application. This, of course, can be unacceptable to many smaller customers who do not have the resources to upgrade their existing network architecture. Thus, there has arisen a need for the ability to provide particular applications to a customer without requiring the upgrading or altering or their existing legacy system.